Apparatus for moistening sand and the like



Ma 1963 cfmmcHALowsKl 3,082,497

APPARATUS FOR MOISTENING SAND AND THE LIKE Filed May 1 1957 5 sheets-sheet 1 BY a March 26, 1963 c. M. MICHALOWSKI 3,

APPARATUS FOR MOISTENING SAND AND THE LIKE Filed May 16, 1957 5 Sheets-Sheet 2 W jml IN V EN TOR.

amp/6 4 March 26, 1963 c. M.- MICHALOWSKI APPARATUS FOR MOISTENING SAND AND THE LIKE Filed May 16, 1957 5 Sheets-Sheet 3 IN V E N TOR.

@zma BY 0 ilnited rates Patent 3,082,497 APPARATUS FER MUESTENING SAND AND THE LllKE ilonrad M. lilichalowski, Chicago, Ill assignor to leiray Machine 8; Engineering Co., Inc, Chicago, 111., a corporation of Illinois Filed May 16, 1957, Ser. No. 659,537 Ciaims. (Cl. 22-89) This invention relates generally to apparatus for moistening granular or pulverulent material and more particularly, relates to improvements in apparatus for moistening molding sand of the type used in foundries.

One of the materials used in modern foundry practice consists of molding sand, which may be either of the natural or synthetic variety, such sand often including other ingredients such as binding materials homogeneously mixed therein. After molding of the article, it is desirable to reclaim and recondition such molding sand for use again. Many problems arise in connection with the treatment of such used sands, one of the chief of which is satisfactory cooling of the hot sands after molding. The flasks, containing the molded article and molding sand, are dumped onto a separator device, such as a screen, which permits the hot sand to pass therethrough free of the article and mold debris. The sand thus separated, however, is too hot for use and not of uniform temperature throughout by reason of the different distances from the molded article which various portions of the sand occupied during molding. Consequently, prior employed practices of merely spraying water on the separated sand were entirely inadequate to cool same sutliciently or rapidly enough for modern continuous molding techniques. The apparatus embodying the invention provides improved, continuously operating means for cooling and moistening such used sand which is especially adapted to be installed in conjunction with a conveyor system in foundries.

An important object of the invention is to provide a new and improved apparatus for cooling and moistening molding sand which includes a liquid spray system and novel regulating means for controlling operation of the spray system, said regulating means being actuated in response to a predetermined height of sand passing the same on the conveyor. An ancillary object of the invention is to provide such regulating means which are adjustable to respond to any one of a number of selected heights for the sand.

Another important object of the invention is to pro vide a novel regulating device for controlling means for moistening such molding sand which by reason of its construction is capable of being advantageously installed along the conveyor system to permit operation thereof in cooperation with other reconditioning equipment installed with the conveyor so as to realize more rapid and efiicient cooling of the molding sand than heretofore has been possible.

A highly desirable feature of the invention is the provision of such improved apparatus for moistening and for cooling molding sands which may be constructed and installed at relatively low cost, which is easy to maintain and which is capable of being operated for extended periods of time without requiring frequent repair and cleaning; and which may be installed in conjunction with already operating conveyor systems without undue modification or alteration of the systems.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel features of construction, arrangement and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, Size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

For the purpose of facilitating an understanding of this invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, this invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.

Referring to the drawings in which the same characters of reference are employed to indicate corresponding or similar parts throughout the several figures of the drawings:

FIG. 1 is an elevational view of a section of a conveyor system along which reclaimed molding sand may be transported for moistening, the apparatus for moistening the sands as embodied in the invention being illustrated installed in conjunction with the conveyor system.

FIG. 2 is a plan view of the installation shown in FIG. 1.

P16. 3 is a vertical section taken through the conveyor system of FIG. 1 at a point in front of the apparatus embodying the invention and looking toward said apparatus.

FIG. 4 is a fragmentary elevational view on the left hand portion of FIG. 1 and enlarged to show the regulating means of the invention.

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 4.

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 4.

FIG. 7 is a perspective view of the regulating means embodying the invention.

FIG. 8 is an enlarged elevational view of the spray nozzle employed in the invention and shown attached to a supply line.

FIG. 9 is an elevational view of another section of the conveyor system and showning the apparatus embodying the invention installed in connection therewith to illustrate another position of use therefor.

FIG. 10 is a schematic illustration of a water supply system to which the moistening apparatus of the invention may be connected.

Referring now to the drawings, illustrated in FIGS. 1 and 10 are two different stations which may be installed along an endless conveyor, such as an endless belt, the upper reach it) of which has been illustrated. In describing the invention, it will be presumed that said reach it) moves from left to right in said figures. Although not shown, it may be understood that the left hand end of the conveyor is advantageously located adjacent a device for separating the hot molding sand from the molding flasks (not shown), such a device comprising generally a screen or grate straddling reach 10 onto which such flasks may be dumped so as to permit only the molding sand to pass therethrough and drop on the reach 10 for further transportation therealong. In conjunction with such a separating device there may be installed a vertically adjustable leveling gate comprising a planar member (FIG. 1) extending transversely across the reach 19 and having its bottom edge spaced above said reach a predetermined distance. As the hot sand drops on the conveyor, it is transported past the gate whereupon said bottom edge of the gate functions to level said sand to a predetermined height. Such a gate is desirable where the height of the sand on the conveyor reach should not exceed a predetermined amount.

The hot molding sand is thus carried at a uniform level toward the novel moistening apparatus of the invention capable of being associated with either or both of the stations illustrated in FIGS. 1 and 10. These stations may be provided individually or in any desired number or combinations along the extent of the conveyor system. One of the important advantages of the invention may be apparent from the suitability of the moistening apparatus embodying the invention to be readily and conveniently installed in conjunction with such stations and hence, at any one of a number of desirable locations along the conveyor system.

Considering the station of FIG. 1, same may be seen to comprise an erect box-like frame designated generally 11 and made of structural members which includes a plurality of upright angle iron standards 12 braced top and bottom by the longitudinally extending, horizontal angle irons 13 and 14 and the transversely extending, horizontal angle irons 15, 16 and 17 (best seen in FIG. 3). The frame members may be suitably conjoined by welding, bolts or other fastening means. The entire station, with its associated equipment, is supported on any suitable longitudinally extending structural beam member 18. Obviously any base can be used.

The reach it} passes through said box-like frame suitably supported by roller members at spaced intervals subtending the same. Idler rollers are illustrated at 21 rotatably installed on the cross-bar 21. Another supporting roller 22 journalled on the L-shaped bracket 23 attached on the support member 18 is illustrated and the number of such rollers may vary. Guide rollers 24 are attached on members 12 to guide the reach in its horizontal passage through the box-like frame. It will be appreciated that the number, placement and construction of the rollers for supporting and guiding the reach 10 may vary within wide limits.

Frame 11 supports a muller roll 25 which usually comprises a hollow cylindrical drum formed from stainless steel which is mounted on a support and drive shaft 26 journalled in the bearings 27 attached on the cross-brace 14. The source of power for driving the muller 25 may comprise a conventional electric motor 28 mounted on the platform 29 secured on top of the frame 11. Said motor includes a gear reduction system encased in the housing 30 which drives the pulley wheel 31 drivingly connected by means of the pulley belt 32 to the pulley wheel 33 carried on the muller roll shaft 26. The peripheral velocity of the muller 25 preferably is selected to be substantially the same as the liner speed of the conveyor belt 10. The mulling action is well understood, same being to spread and compact the granular sand transported on reach 10 into a compact, uniform layer.

The muller 25 is supported inside the frame 11. Suitable enclosure plates may be provided, such as side Wall plates 34, as seen in FIG. 3, to prevent the molding sand from being scattered out of the frame. To the right-hand uprights 12 is attached a housing 35 made of sheet metal, said housing straddling the reach 10 and being open at its forward end to receive the molding sand after being acted upon by the muller 25. The housing 35 may be seen to be substantially triangular-shaped and normally closed at the top thereof and having a door 36 through which access to the interior of the housing is obtainable. A reduced dimension skirt 37 attached to each side of the housing 35 cooperates to form a narrowed passageway 38 through which the molding sand is carried out of the housing, the skirts 37 funnelling the sand toward said passageway and away from the lateral edges of the reach 10.

Although the frame 11 has been illustrated as supporting a single muller 25, it should be understood that more than one muller roll may be installed in the frame. Also, the particular structure of the muller roll and the manner of mounting and operating same may vary considerably. The important feature is that moistening and mulling occur almost simultaneously.

The specific apparatus supported in such a frame 11 also may vary and in this connection reference is directed to FIG. 10. The box-like frame 40 may be considered to be substantially identical in construction to frame 11 in that same comprises a box-like structure formed of frame members suitably interconnected. However, the frame 40 is illustrated as supporting on the interior thereof a pair of rotatable agitators in the form of cutters 41 which comprise curved or helical metal blades suspended above the reach 10. The cutters 41 are driven from an electric motor shown at 42 by suitable pulley and drive belt apparatus (not shown) at an angular velocity substantially greater than the linear speed of reach 10 and due to the curvature of the blades thereof, the sand carried on the reach '10 under the cutter blades is aerated and fiuifed. Suitable enclosure wall plates for the frame 40 may be provided to prevent scattering of the granular material during flufiing thereof.

After the agitator action of the cutters, the sand is carried into the housing 43 straddling the reach at the righthand end of frame 40 to be mulled. For this purpose, a muller stage designated generally 44 is supported inside the housing 43. The muller 45 of said stage is electrically driven from the motor 46, muller 45 being rockably mounted on the rocker support bar 47 in accordance with the principles disclosed in Letters Patent No. 2.,610,-.

373, issued September '16, 1952, to Jules T. Parisi. It is contemplated that the manner of mounting muller stage 44 may vary also to include a non-rocking type installation in lieu of muller 45 or more than a single muller roller, as illustrated.

The apparatus per se heretofore described is well known and comprises agitator and/or muller stages installed at intermittent locations along a conveyor line in foundries. Further details of construction are available from said Letters Patent No. 2,610,373, although it is not intended that the invention be limited to such constructions.

Specifically, the invention resides in the combination of a moistening aparatus with either a muller stage or a combined mixer-muller stage to obtain entirely unexpected and highly desirable advantages in the cooling and moistening of molding sands. The moistening apparatus embodying the invention includes a regulating device designated generally 50 in FIG. 7 for controlling the spraying of cooling liquid, such as water, from a supply system, such as designated generally 51 in PEG. 9. The details of said apparatus 50 follow:

The regulating device 50 is attached to the frame 11 to project forwardly thereof or to the left as seen in FIG. 1 or 10 by means of a horizontally arranged, longitudirially extending stringer 53, one end of which is secured to the frame by means of the angle iron 16 and bolts 54, or Welding, if desired. The opposite end of the stringer carries a rigidly attached mounting bracket 56, said bracket 56 having protruding ear 57 integral therewith extending forwardly of the mounting bracket. Said ear 57 has a passageway therethrough in which is slidably engaged threaded shank 59 of manually operable handle 60, the nuts 58 engaging on opposite sides of the ear 57 with said shank 59 threadedly engaged therethrough. Rotation of the handle 60 will result in axial movement of the shank relative said ear 57.

The lower end of the shank 59 is threadedly engaged through another perforated ear 58 rigidly secured on the elongate plate 61 aligned with the car 57 and similar nuts 53 are employed.

Plate 61 is disposed with the plane thereof vertically arran ed and spaced above the reach it) and extending longitudinally of the reach it). To the bottom edge of the plate at is pivotally attached the actuator means 62 for controllin operation or" the moistening apparatus.

Referring to FIG. 7, the actuator means 62 may be seen to include a rocker arm or plate 63 of generally triangular configuration having the apex of the triangle truncated to provide a narrowed end 64 and wider end 65. The end 64 of said plate 63 is rigidly secured, as by welding to the bushing 66 which is journalled for rotation on the shaft 67 supported in a bearing in plate 63 and the bearing plate 68. The bearing plate 68 is substantially L-shaped so as to enable a leg 69 thereof to be rigidly attached to a surface of the plates 61 and 56. The wider end as is connected to a pan '70, the bottom wall of the pan being angularly disposed relative the plate 63. Secured to a medial portion of the plate 63 is a standard 72 on the upper edge of which is attached a metal strip 73, the planes of the strip '73 and the wall 71 of the pan being parallel. The inner end of said metal strip 73 is rigidly secured, as by welding, to the bushing 66 as indicated at 74. The opposite end 75 of the strip protrudes outwardly of the standard 72 and has a hole therethrough in which is threadedly engaged a bolt 76. The

axis of the bolt is perpendicular to the plane of strip 73.

The head '77 of said bolt extends outwardly of the upper surface of the strip 73 and a lock nut 78 screwed on the shank of the bolt enables same to be locked in any one of a plurality of positions in said protruding portion 75.

It will thus be seen that the actuator assembly 62 is mounted for independent pivotal movement about the end 64 of said plate 6'5 and that the pan 7%, standard 72, strip 73 and bolt "/5 are movable therewith as a unit relative the fixed plate 61. On the other hand, the actuator assembly and the plate 61 are together movable vertically relative the stringer 53 when the handle as is rotated either to advance or retrac the shank 59 in the coaxially aligned sleeves 58 and 58'.

The plate 61 has a reduced dimension end 80 which is spaced above strip 73 and to which is mounted an electrical switch S1. The electrical switch 81 preferably comprises a sensitive microswitch and is mounted with its contact button 82 depending toward the head 77 of bolt 76 and aligned therewith so that said but-ton may be engaged by the head 77 under prescribed circumstances to close said switch. The electrical conductor 83 connects the switch to a control valve of the supply system 51.

Referring to FIG. 4, it will be seen that the regulating device 56 is installed on the uprights 12 which face opposite the direction of movement of reach 10, namely, from left to right in the figure. The regulating device therefore extends forwardly of the frame it in a position to intercept sand 3 moving toward the frame. As previously explained, after the sand 34 ha been separated from the molding flask-s, it is collected on the reach it) and leveled off by a suitable leveling gate. This is indicated by the fiat top surface 85 of the sand 34 which is arranged a predetermined distance above the reach it Prior to the time same is engaged by the sand 84, the actuator means 62 will hang freely down with the pan 7% disposed in the path of movement of the sand 84. As the leading edge of the sand engages the actuator means, it raises the pan 7t so that the bottom wall 71 thereof comes to rest on the surface 85. The strip 73 is moved in a direction away from the reach it) and thereby moves the head '77 of the bolt 76 into engagement with button 82. to close switch 81. it thus will be apparent that so long as the pan 7% rests on the upper surface 85 of the sand transported on the belt 10, the switch 81 will be kept closed.

Since the plate 61 with the actuator means 62 attached thereon are movable as a unit relative stringer 53 by means of the handle 60 and since the bolt 76 is adjustable relative the switch button 83, it will be apparent that the height of the sand 84 may be varied and still affect operation of the regulating device 50. Suitable adjustment in the regulating device is permissible to achieve closing of switch 81 by the bolt '76 under such circumstances. This may be desirable since the amount of sand carried by the conveyor may vary for different molding operations. A prime consideration is speed of cooling of the sand 84- as well as efficient, thorough cooling thereof and hence, it may be desirable to achieve cooling operations of the equipment where the sand S4 is at a lower level on the reach iii. In this connection, the actuator means may remain adjusted for a higher stand of sand than is being carried where such reduced quantities of sand do not require moistening.

Closing of switch 81 initiates the spraying of a cooling liquid on the sand 34 entering the frame 11. The liquid may be supplied from a system 51 such as illustrated in FIG. 9. The line 87 is connected to a source of water under pressure (not shown), said line including a plurality of suitable valves for controlling the pressure at which the water is dispensed. A pressure regulation valve 88, a solenoid-operated control valve 89 and gate valves 9t) are illustrated, one of said gate valves 90 being installed in the by-pass 11 connected between the coupling Ts 92 connected in the line 87. The pressure gauge 93 enables reading of the line pressure as adjusted by valve 88. Installed on the free end of line 87 is an elbow 94 to which is connected a nozzle 95. The nozzle 5 is arranged in the installation of either FIG. 1 or FIG. 10 so that the spray 96 therefrom covers the entire surface of the sand 84 transported therebeneath. As seen in FIG. 9, the nozzle overlies the longitudinal center line of the belt 1d so that the sand 84 on each side of said center line will be wetted by the spray 96. FIG. 9 also shows the conductor 83 connected to the solenoid valve 89 which is normally maintained in a closed condition. Thus, when the switch 81 is closed, the valve 89 is opened to permit spraying of the sand 84 from nozzle 95. Plates channel the sand below the nozzle.

Referring to FEGS. l and 4, it will be seen that in connection with the mulling station illustrated, the nozzle 95 has been connected at the end of a reducer pipe 96 which connects at its opposite end with the elbow 94 seen in FIG. 9. The nozzle 95 is located immediately behind the uprights 12 at the front end of the frame 11. Thus, as the sand 84 raises the pan 70 to close switch 8-1, the solenoid valve 89 is opened. The sand 84 passes into the frame 11 and the spray 96 from nozzle 95 covers the entire upper surface 85 as the sand passes thereunder. Thus, the sand 84 is wetted and immediately thereafter, the wetted sand is subjected to the mulling action of muller roll 25. The combined wetting action of the spray 96 and the mulling immediately thereafter by roller 25 achieves a more eh'icient, homogeneous and rapid cooling of the sand 84. The high degree of efiiciency is achieved by reason of the combined action of the spray 96 and mulling and is substantially greater than achieved merely by spraying of water on the sand, as has been the previous practice in the art.

The installation of FIG. 10' is of the type which may be required for certain types of synthetic molding sands, such sand being designated 1W. In this installation, sand usually is prepared for molding by having certain binders, etc. admixed therein at some stage previous to reaching the frame 40. Same requires moistening prior to being used in molding. However, by reason of its synthetic character, proper moistening requires the water to be added carefully. In this instance, the nozzle 95 may be seen to have been mounted at the rear. end of the frame 44% to spray into the housing 43. Thus, sand 1% first actuates the regulating device 50- and the sand 1% is intercepted by the cutters 41 which tosses the sand considerably to insure proper mixture and aeration. After cutting action on the sand 1%, same passes out of the frame 41} into the housing 43 where it is Wetted by the spray 96. immediately thereafter it is mulled by muller station 44. Where natural sand is being transported by the reach 10, the nozzle 95 preferably would be installed at the front end of the frame 4% to spray the sand Hit} prior to same entering the frame 40. The reason for this change in position is because natural sand already contains a certain quantity of moisture and hence it is desired that the sand be wetted from nozzle 95 prior to being tossed by cutters 41.

It will thus be appreciated that by reason of the novel structure of the regulating means 50, same is capable of being installed in cooperation with either mulling or agitating equipment of a conveyor system in foundries for conditioning molding sand. The nozzle 95, operation of which is controlled by said means Sil, is capable of being selectively installed at any one of a plurality of positions to Wet desired types of sands carried by the conveyor. This enables the wetting of the molding sands to be achieved in conjunction with conditioning equipment which can immediately mull or agitate the molding sand. Thus, the invention contemplates apparatus which will rapidly and eiriciently cool or moisten molding sands or which can condition sands preparatory to use thereof for molding. In either case, the wetting of the sand can be achieved at selected locations along the conveyor system for the most satisfactory results regardless of the type or qiiantity of sand being used. In addition, the regulating device 50 may be adjusted to control the wetting op eration where the quantities of transported molding sand are small or large, adjustment of the device 59 being related to the height of sand on the conveyor belt. This may be predetermined by means of the leveling gate (not shown) at a location on the conveyor reach ahead of the device 50. The invention facilitates continuous operation of the conveyor system at high speed.

It is believed that the invention has been described in sufficient detail to enable same to be understood and practiced by the skilled artisan as contemplated by the patent statues. The broad principles of the invention have been set forth in the claims hereto appended, it being desired that these claims be construed most favorably commensurate with the progress over the arts and sciences contributed by the invention.

I claim:

1. A device for controlling the spray of liquid from a nozzle to wet the surface of a layer of sand carried on the reach of a conveyor, a rocker arm connected at one end thereof for free rotation on an axis spaced above and parallel to the reach, the opposite end of said arm being angularly disposed relative the body of the rocker arm and presenting a planar wall portion adapted to ride on said surface, said device having movable control means adapted to be connected to control opening and closing of the nozzle, said rocker arm having an extension thereof disposed perpendicular to said planar wall and spaced thereabove, said extension being adjustable relative said planar wall portion permitting the nozzle to be opened only when the planar wall portion is moved to said position at a predetermined height above the conveyor reach, said device adapted to be mounted with the rocker arm projecting into the path of movement of the sand to permit the sand to move the planar wall portion to a position engaged upon said surface whereupon said extension will be moved into engagement with the control means to maintain the spray nozzle open.

2. A device as described in claim 1 including adjustment means comprising an intermediate support plate having said rocker arm attached thereto, a mounting bracket movable in a direction susbtantially normal to .said reach, said supoprt plate being connected to said bracket for movement with the attached rocker arm relative said mounting bracket in a direction substantially normal to the reach, said extension adapted to be moved relative said planar Wall to vary the distance required by the planar wall to be moved to enable said extension to engage the control member.

3. Apparatus for moistening molding sand carried on a conveyor comprising, in combination, an aqueous liquid supply system including a nozzle for spraying said liquid on the sand from a point spaced above the belt and a control valve for opening and closing said nozzle, an adjustable regulating device connected to operate the valve to open said nozzle when the sand on the reach of the conveyor is at a predetermined height, said device including a bracket for mounting same in conjunction with the conveyor spaced above the reach thereof, an elongate support plate connected to said bracket for movement toward and away therefrom, a rocker arm pivotally connected at one end thereof to the bottom edge of said support plate and having a first portion diagonal to the reach and its opposite end flattened and angularly disposed relative said first portion, said flattened end adapted to be arranged in the path of movement of the sand to be moved upon engagement of the sand therewith to a position on top of the sand, said arm having movable extension thereof spaced above said flattened portion and said support plate having a normally open electrical switch located to be closed upon engagement thereof with the said extension, electrical conductor means connecting the switch to said control valve, said support plate and extension beingadjustable to permit closing of the switch only when the sand is at said height,

4. In a conveyor system for transporting granular or pulverulent material required to be cooled prior to use thereof and having material leveling means straddling the conveyor to prevent material transported on the conveyor exceeding a predetermined height and a conditioning apparatus stationed therealong through which said material is passed for mulling or aerating said material, means for applying an aqueous spray to the upper surface of the material, said spraying means located adjacent said conditioning apparatus so that the material is conditioned and moistened in immediate succession, said device including rockable actuating means normally disposed in the path of movement of the material to be engaged and moved by the material to a position rendering the spray means operative only when the material is at said predetermined height, said actuating means being vertically adjustable relative to the conveyor to control operation of the spray means also at other predetermine heights, and automatically movable to a position rendering the spray means inoperative when the height of said material is less than said predetermined height, said actuating means being located to be so engaged prior to entry of the material into the conditioning apparatus whereby operation of the spray means and conditioning apparatus occur in immediate succession to uniformly and rapidly cool said material, said actuating means including a rocker arm freely pivotal at one end thereof on an axis spaced above and normal to the path of movement of the material, said arm having an opposite planar extremity adapted to ride on the upper surface of said material in the first mentioned position of the actuating means, said regulating device including a mounting bracket for installing same on said conditioning apparatus and an intermediate support member connected to said bracket for movement relative thereto along a path perpendicular to said conveyor, said rocker arm being connected to said support member for such relative movement therewith, said device having a movable control member operatively connected to operate said spray means and said rocker arm having an extension thereof spaced above and perpendicular to said extremity adapted to engage said control member in said first mentioned position of the actuating means whereby to move same to render the spray means operative.

5. In a system as described in claim 4 in which said 1,534,331 Simpson Apr. 21, 1925 control member and extension are adjustable in their 2,273,126 McGillin Feb. 17, 1942 linear displacement one relative to the other. 2,338,081 1944 2,610,373 Parisi Sept. 16, 1952 References (Iited in the file of this patent 5 2,778,076 Bell Ian. 22, 1957 UNITED STATES PATENTS 2,848,098 Dlfitel t (ital Aug. 19, 1958 762,596 Packer June 14, 1904 FOREIGN PATENTS 1,381,107 Cwirko June 14, 1921 483,371 Germany Oct. 10, 1929 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 O82 497 March 26 1963 Conrad M. Michalowski It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5 line l6 for "63" read 61 line 19, for "plates 61 and 56" read plate 61 line 43, for sleeves 58" read ears 57 column T line 74, for "supoprt" read support;

Signed and sealed this 29th day of October 1963.

(SEAL) Attest:

ERNEST W. SWIDER EDWIN L. REYNOLDS Attesting Officer AC ting Commissioner of Patents 

1. A DEVICE FOR CONTROLLING THE SPRAY OF LIQUID FROM A NOZZLE TO WET THE SURFACE OF A LAYER OF SAND CARRIED ON THE REACH OF A CONVEYOR, A ROCKER ARM CONNECTED AT ONE END THEREOF FOR FREE ROTATION ON AN AXIS SPACED ABOVE AND PARALLEL TO THE REACH, THE OPPOSITE END OF SAID ARM BEING ANGULARLY DISPOSED RELATIVE THE BODY OF THE ROCKER ARM AND PRESENTING A PLANAR WALL PORTION ADAPTED TO RIDE ON SAID SURFACE, SAID DEVICE HAVING MOVABLE CONTROL MEANS ADAPTED TO BE CONNECTED TO CONTROL OPENING AND CLOSING OF THE NOZZLE, SAID ROCKER ARM HAVING AN EXTENSION THEREOF DISPOSED PERPENDICULAR TO SAID PLANAR WALL AND SPACED THEREABOVE, SAID EXTENSION BEING ADJUSTABLE RELATIVE SAID PLANAR WALL PORTION PERMITTING THE NOZZLE TO BE OPENED ONLY WHEN THE PLANAR WALL PORTION IS MOVED TO SAID POSITION AT A PREDETERMINED HEIGHT ABOVE THE CON- 